diff --git a/wgt01/wire_materials.py b/wgt01/wire_materials.py
index b223f6c..cc7dde2 100644
--- a/wgt01/wire_materials.py
+++ b/wgt01/wire_materials.py
@@ -6,6 +6,7 @@ BASE = os.path.dirname(bpy.data.filepath)
 for slot in SLOTS:
     name = f"MAT_wgt01_{slot}"
     mat = bpy.data.materials.get(name) or bpy.data.materials.new(name)
+    mat.use_fake_user = True
     mat.use_nodes = True
     nt = mat.node_tree; nt.nodes.clear()
     out = nt.nodes.new("ShaderNodeOutputMaterial")